In order to know the health status in workers exposed to low-level benzene, 323 air samples were collected from five workshops of the Corporation, where low-level benzene was emitted from aromatic hydrocarbon devices. Results showed air benzene levels ranged from 0.05-29.25 mg/m3, with an average of 4.57 +/- 6.16 mg/m3, and the highest in the benzene-producing workshop. Four hundred and thirty-seven workers closely-exposed to benzene in five workshops and 150 controls were selected and their peripheral white blood cell count and micronucleus of lymphocytes were determined. Result showed that 1. peripheral white blood cell count of the exposed workers was within the normal range, but obviously lower than that of the controls; 2. proportion of lymphocytic micronucleus was higher in exposed workers than that in unexposed ones, and there was significant difference in it between workers in benzene-producing workshop than that in controls; 3. white blood cell count lowered and proportion of lymphocytic micronucleus increased in the workers, with the increase of air benzene level in the five workshops. All these demonstrate that low-level benzene is harmful to the exposed workers, especially to their genetic materials.